This is fantastic in every way. The hardest part of participating for me was finding more time closer to the holidays as the challenges got harder. Fewer, better challenges, with more space between them and the end of the year is a brilliant solution. So excited and grateful.
Fewer challenges, but no more space between them. They still come out daily starting December 1st. They just stop coming sooner.
Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
191–200 of 226 posts
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#192Earlier quoted context omitted.
When my kids move out, one of my plans is to finally start the first Advent of Code.
you'll have a new set of excuses then, too.
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#193> If you're still stuck, maybe ask a friend for help, or come back to the puzzle later. You can also ask for hints in the subreddit. Not sure why this is OK but prompt engineering isn't? If someone wants to test that skillset, let them be instead of asking 'please don't'. Especially given the competitive nature is now optional.
In practice, nothing prevents you from using AI to solve the problems anyway.
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#194But since this is the first time I’ve been to the site, I’ve never seen it before. Oh my God it’s completely unreadable.
Seems only FF supports alternate stylesheets, so that’s not a useful solution for me.
Shame. I’m not going to fight that hard to read a website. I’m really sorry, readability is just table stakes.
Oh well.
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#195This prompted me to try out claude code on last years... To absolutely no surprise, it looks like the model was trained on advent of code. For the day 2 challenge, I put in this prompt: for each row in input.txt, identify all the rows where: 1. the columns either all increase or decrease 2. the increase/decrease is >1 and It solved it very quickly. However... It's solution code included this comment: Check if a repor…
Follow up: > how did you know to call them reports and levels? Good catch! I noticed that terminology in the input file structure. When I read input.txt, I saw the data format - each row contained multiple space-separated numbers. I actually made an assumption based on common Advent of Code patterns (this looks like a typical AoC problem structure). The terms "reports" and "levels" aren't explicitly stated in your re…
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#196I’ve always wanted to try this, but I always seem to end up hearing about it too late. This sounds like a nice change to me. But since this is the first time I’ve been to the site, I’ve never seen it before. Oh my God it’s completely unreadable. Seems only FF supports alternate stylesheets, so that’s not a useful solution for me. Shame. I’m not going to fight that hard to read a website. I’m really sorry, readability…
Most browsers have a “reader mode” which might help you.
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#197Earlier quoted context omitted.
Fewer challenges, but no more space between them. They still come out daily starting December 1st. They just stop coming sooner.
Now it’s The 12 Days of Code.
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#198One of the reasons I stopped participating was that as the second half of december was approaching I had less and less free time for solving the puzzles. So to me it is also a welcome change, I will try to finish it again this year.
I once has this half serious idea to do "Advent of Parenting", with one problem per month, and you start after Christmas. As in, youre so delayed you start in the New Year, and have time for one problem per month. But hey I didn't have the time to do it. Kids...
Yep, dont have the kids. And no plan to.
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#199I see the leaderboard is gone too. Unfortunate but entirely predictable given how the last 2 years went. That being said, I was worried he'd cancel the entire thing, so this is still good news!
Gonna miss it. So fun to see how fast one can parse the problem, figure out how to solve it while thinking of edge cases, and then actually write and run it. I've never been high up on the leaderboard, but enjoyed waking up early in December and give it a crack. Most often rank ~1000, a few times ~100. But I also understand the decision. Fun while it lasted, but I'll find other ways to have fun with AoC this year!
It’s like excitedly arriving to a potluck with your beef bourguignon, only to find twenty michelin-starred chefs competing against each other.
Not exactly my idea of “fun” :) to me AoC was much more of a neighborhood party than an olympic event.
Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time
#200This is fantastic in every way. The hardest part of participating for me was finding more time closer to the holidays as the challenges got harder. Fewer, better challenges, with more space between them and the end of the year is a brilliant solution. So excited and grateful.
Why did the number of days per event change? It takes a ton of my free time every year to run Advent of Code, and building the puzzles accounts for the majority of that time. After keeping a consistent schedule for ten years(!), I needed a change. The puzzles still start on December 1st so that the day numbers make sense (Day 1 = Dec 1), and puzzles come out every day (ending mid-December).